Received my 1070 on Thursday...I'm using it to drive a pair of Monitor Audio RS6's for now (adding the rest of a 5.1 setup later on, subwoofer might wait til I'm out of an apartment though), and it sounds great. I know it's not entirely a fair comparison since it's in my room now (and my memory just isn't good enough to accurately compare two things I heard a week apart), but I'll say I'd be hard pressed to point out any way in which it is significantly outperformed by the equipment I was listening with when auditioning speakers in the shops (equipment which has another digit or two in the price, too).
There are two minor issues I have with it though. The first seems like it might be related to the "no audio" issue I've seen mentioned on here...whenever I plug in headphones, I have to switch the source a few times before I can hear anything. I haven't noticed this behavior with the regular speakers yet.
The second is that the "external 7.1" can apparently only be associated with the "dvd" input. While this isn't really an issue right now (given that I have a stereo setup for the moment), it would be nice if it could be used with the "cd" input as well...I have a universal disc player, which I want to use the optical output of for DVDs and CDs, and (eventually) the 5.1 output for SACDs...to make this work, it looks like I'm going to have to use the CD input for DVDs and the DVD input for SACDs, which just seems unnecessarily counterintuitive. Is there some reason the inputs are set up this way?